Al Horford will see action for the Celtics before their regular season debut against the Knicks on Oct. 22 despite sitting out the team’s first four preseason games. The 38-year-old sat out with the remainder of Boston’s usual starting five on Sunday night against the Raptors at TD Garden but there is no cause for concern about the big man.

Though he made his Celtics debut more than a week earlier, Saturday night was Lonnie Walker IV’s first real opportunity to prove himself to Boston’s decision-makers. The veteran wing played a team-high 25 minutes in the Celtics 139-89 throttling of the Philadelphia 76ers at TD Garden,